بذه عن الكتاب: As a premise to this textbook on Numerical ecology, the authors wish to state their opinion concerning the role of data analysis in ecology. In the above quotation, Goethe cautioned readers against the use of mathematics in the natural sciences. In his opinion, mathematics may obscure, under an often esoteric language, the natural phenomena that scientists are trying to elucidate. Unfortunately, there are many examples in the ecological literature where the use of mathematics unintentionally lent support to Goethe’s thesis. This has become more frequent with the advent of computers, which facilitated access to the most complex numerical treatments. Fortunately, many other examples, including those discussed in the present book, show that ecologists who master the theoretical bases of numerical methods and know how to use them can derive a deeper understanding of natural phenomena from their calculations. Numerical approaches can never dispense researchers from ecological reflection on observations. Data analysis must be seen as an objective and non-exclusive approach to carry out in-depth analysis of the data. Consequently, throughout this book, we put emphasis on ecological applications, which illustrate how to go from numerical results to ecological conclusions. This book is written for the practising ecologists — graduate students and professional researchers. For this reason, it is organized both as a practical handbook and a reference textbook. Our goal is to describe and discuss the numerical methods which are successfully being used for analysing ecological data, using a clear and comprehensive approach. These methods are derived from the fields of mathematical physics, parametric and nonparametric statistics, information theory, numerical taxonomy, archaeology, psychometry, sociometry, econometr